SDN Deep Dive Series – Part 2: Use Cases, Deployment, and Integration

July 2013   |   Reading Time: 12 minutes

In Part 1 of our Software Defined Networking (SDN) deep dive, we dissected the fundamentals and explored the architectural principles. Today, we explore practical SDN use cases, deployment realities, and integration with existing infrastructure.

Why SDN Matters Now

SDN enables unprecedented network agility, allowing administrators to reprogram data flows in real time. This flexibility is pivotal in data centers, service provider backbones, and enterprise WANs where dynamic traffic behavior demands rapid adjustment.

Use Case 1: Multi-Tenant Data Centers

Data center operators hosting cloud environments must ensure traffic segmentation, tenant isolation, and scalable routing. Traditional VLAN-based segmentation runs into scalability limits. SDN introduces programmatic overlay networks using tunneling protocols like VXLAN and NVGRE.

• Dynamic path computation using traffic policies
• Automated provisioning and teardown of tenant networks
• Improved visibility and security posturing

Use Case 2: Campus Networks

Enterprise campuses struggle with consistent policy enforcement across switches. SDN centralizes access control policies, allowing intent-driven networking where administrators define what should happen, not how to configure individual devices.

Use Case 3: WAN Optimization and Path Control

Branch connectivity often relies on MPLS or IPsec tunnels. SDN can dynamically reroute traffic based on cost, link quality, or congestion. By abstracting path decisions from hardware, operators gain control over application flows in hybrid WANs.

Integrating SDN into Existing Networks

Most organizations won’t rip and replace legacy infrastructure. SDN must interoperate with existing routing protocols, physical switches, and firewalls. This integration requires hybrid models:

• Overlay SDN: Using tunnels over IP to create virtual topologies
• Hybrid SDN: Coexistence of OpenFlow-controlled and traditional devices
• Service Chaining: Routing traffic through firewalls, IDS/IPS using SDN paths

Deployment Challenges

Despite the promise, SDN deployment faces practical hurdles in 2013:

• Controller Selection: No single OpenFlow controller has emerged as a clear winner
• Interoperability: Varying vendor support and OpenFlow versions hinder standardization
• Skill Gap: Network engineers must acquire programming and API knowledge
• Security: Centralized control plane creates new threat vectors

Tooling and Ecosystem Maturity

The SDN ecosystem is rapidly evolving. Notable players include:

• Floodlight: An open-source Java-based OpenFlow controller
• NOX and POX: Research-oriented Python frameworks
• Mininet: A powerful network emulator used for prototyping SDN topologies

Vendors like Cisco, HP, NEC, and Big Switch Networks offer hybrid switches and platforms, though interoperability varies widely.

Planning for SDN Adoption

Successful SDN adoption requires a phased approach:

1. Define target outcomes (e.g., improved visibility, traffic steering)
2. Select pilot environments (e.g., lab, edge switches, or isolated VLANs)
3. Train engineering teams on OpenFlow, controller APIs, and automation tools
4. Evaluate vendor support for hybrid SDN integration

Conclusion

SDN is no longer theoretical—it is evolving into a deployable technology. By aligning SDN use cases with real network needs, organizations can deploy incrementally while reducing operational complexity and improving responsiveness.

Eduardo Wnorowski
With over 18 years of experience in IT and consulting, he helps businesses simplify network complexity while improving visibility and control.
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